title: Effect of magnetic hyperthermia on the structure of biofilm and cellular viability of a food spoilage bacterium.
abstract: This work evaluated the effect of magnetic hyperthermia (MH) on planktonic cells and biofilms of a major food spoilage bacterium Pseudomonas fluorescens and its performance compared to a conventional direct heating (DH) technique. The results showed that MH had a greater and faster bactericidal effect, promoting a significant reduction in cell viability (≥3 Log CFU) in planktonic and biofilm cells, and leading to a complete eradication of planktonic cells at 55 °C (after only ~8 min). Accordingly, when comparing the same final temperatures, MH was more harmful to the integrity of cell membranes than DH, as observed in confocal laser scanning microscope images. Additionally, scanning electron microscope images revealed that exposure to MH had promoted modifications of the bacterial cell surface as well as of the structure of the biofilm. These results present the possibility of using MH out of the biomedical field as a potential disinfection method in food-related environments.
authors.affiliation: a Institute for Biotechnology and Bioengineering, Centre of Biological Engineering , University of Minho , Braga , Portugal ;
authors.forename: D
authors.initials: D
authors.lastname: Rodrigues
authors.forename: M
authors.initials: M
authors.lastname: Bañobre-López
authors.forename: B
authors.initials: B
authors.lastname: Espiña
authors.forename: J
authors.initials: J
authors.lastname: Rivas
authors.forename: J
authors.initials: J
authors.lastname: Azeredo
mesh_terms: D018441:Biofilms; D057219:Biofouling; D002462:Cell Membrane; D003080:Cold Temperature; D005516:Food Microbiology; D008855:Microscopy, Electron, Scanning; D011551:Pseudomonas fluorescens / Q000502:physiology*; D013499:Surface Properties